Varnish



Patented Apr. 19, 1938 PATENT. OFFICE VARNISH Fred H. Lane, Hillsdale, N. Y., assignor to Hercules Powder Compa y, Wilmington, DeL, a corporation of Delaware No Drawing. Application May 31, 1935, Serial No. 24,355

10 Claims.

This invention relates to an improved varnish and more particularly to varnish made from extracted pine wood pitch.

Extracted pine wood pitch, which is complex resinous material whose exact composition is un-' known, comprises the residue left after the separation of rosin, turpentine and other more valuable constituents of pine wood. It has heretofore been considered substantially commercially valueless and accordingly has ordinarily been discarded.

Now in accordance with this invention it has been found possible to formulate valuable varnishes from pine wood pitch, drying oils, such as linseed oil, China-wood oil, etc., and solvent thinners. While rosin and oxidized rosin have heretofore been used in the production of varnishes, it has not previously been possible to formulate pine wood pitch into a varnish because of the slight solubility of this material in the usual varnish ingredients. In accordance with this invention pine wood pitch is formulated into varnishes by the use of special solvents which have been found suitable for this purpose.

The pine wood pitch forming the essential ingredient of varnishes in accordance with this invention, as has been indicated, is obtained in connection with the production of wood rosin from pine wood. The pine wood pitch will comprise, a residue low in abietic acid remaining after the separation of refined rosin, high in abietic acid from the resinous material obtained by extraction of pine wood with a solvent; It is characterized by substantial insolubility in cold petroleum hydrocarbons, but will difier somewhat in its specific characteristics, such as acid number, melting point, exact petroleum ether solubility and content of naphtha and toluol soluble matter, depending upon the method for the recovery of rosin from pine wood used in its production.

As is well known, rosin is extracted from pine wood by the use of a suitable solvent, such as hot gasoline benzol after steaming of the wood with live steam to remove volatile oils, such as turpentine and pine oil. Again, volatile oils, as turpentine, and pine oil, are extracted with the rosin without first steaming for their removal. Following extraction the extract is distilled for the removal of solvent where the wood was subjected to steaming before extraction and for the removal of solvent and volatile oils, as turpentine and pine oil, where the wood was extracted directly without steaming. As the result of distillation a resinous material containing abietic acid and admixed impurities is obtained. This resinous material may be treated in any one of a number of ways, all known to the'a'rt, for the removal of refined rosin high in abietic acid. The residue remaining after the removal of re- 5 fined rosin and comprising a dark colored; hard, resinous mass, low in abietic acid, constitutes the pine wood pitch, the essential ingredient of the varnishes constituting this invention.

The exact properties-of the pine wood pitch obtained as indicated above will depend upon the method used for original extraction from the wood. When the wood is steamed before solvent extraction, a pine wood pitch is obtained having somewhat different properties from that obtained when the wood is extracted without steaming. Likewise the properties of pine wood pitch are somewhat different when obtained by different methods of purification of rosin. A comparison of the properties of three pine wood 0 pitches is given in the following table, in which Pitch A is that obtained by extraction of wood with hot petroleum solvents subsequent to the removal of the volatile oils by steam distillation, refining with furfural, evaporation of the fur- 25 fural and a final extraction of the residue with petroleum solvent to remove petroleum soluble matter. Pitch B is that obtained by a bcnzol extraction of unsteamed wood, evaporation of the bcnzol solution to a residue, extraction of the residue in hot low boiling petroleum solvent, precipitation of the Pitch B by washing with cold water, and then removal of this precipitate by filtration. Pitch C is obtained by the evaporation of the furfu'ral layer, after refining of the gasoline solution of the crude resin obtained by the bcnzol extraction of pine wood.

Pitch A Pitch B Melting point (Hercules drop mcthod) Acid number Unsaponifiable matter V. M. & P. naphtha insoluble Toluol soluble.- Petroleum ether insoluble. iaponification number etc. will be added. Other resins used in the var- 51s nish-making art may be included along with the pine wood pitch if desired.

The volatile solvent or thinner used in the formulation of the varnish in accordance with this invention will comprise essentially a mixture of hydrogenated petroleums. These hydrogenated petroleums are described in U. S. Patent No. 1,977,932 and may be prepared by the methods there outlined, although it is contemplated to use hydrogenated petroleums however produced.

The various ingredients of the varnish in accordance with this invention, namely pine wood pitch, drying oil, thinner, driers, etc., may be combined in widely varying amounts, depending upon the particular use to which the varnish is to be adapted. In general, the quantities of the various materials employed in the production oi varnishes according to this invention, as well as the method of combining these materials, will follow those generally in use in the production of varnishes from various varnish resins and drying oils.

The following example is illustrative of the formation of a varnish in accordance with this invention:

100 grams of extracted pine wood pitch and 125 cc. of China-wood oil are heated to 250 C. and held there for 15 minutes. 10 grams of manganese linoleate are then added and the mixture cooled to thinning temperature (about ZOO-210 C.) and 20 grams of lead linoleate and 500 cc. of hydrogenated petroleum solvent are added.

This varnish is air drying and is suitable for general use. In general, the hydrogenated petroleum solvent will possess a medium evaporation range but for industrial varnishes it is frequently desirable to replace a, portion of the petroleum solvent with xylol or high-flash naphtha.

The formula given above shows the same relative proportions as would be used in the manufacture of a fifteen gallon China-wood oil varnish containing fifteen gallons of oil to one hundred pounds of extracted pine wood pitch. If the amount of China-wood oil is increased to twentyfive gallons or more per one hundred pounds of extracted pine wood pitch without increasin the amount of drier, a quick baking varnish is obtained which is resistant to boiling water,

acids and alkali.

It will be understood that the details and examples hereinbefore set forth are illustrative only and are not in limitation of the invention as herein broadly described and claimed.

What I claim and desire to protect by Letters Patent is:

l. A varnish, characterized by its resistance to the solvent efi'ects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble resin obtained by first extracting pine wood with a coal tar hydrocarbon solvent, second removing the volatile constituents from said extract and leaving a residual resin, then third extracting from said residual resin and by means of a petroleum hydrocarbon solvent thepetroleum-soluble non-volatile constituents of said residual resin; a drying oil, and a volatile solvent for said residual resin.

2. A varnish, characterized by its resistance to the solvent effects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble resin obtained by first extracting pine wood with a coal tar hydrocarbon solvent, second removing the volatile constituents from said extract and leaving a residual resin, then third extracting from said residual resin and by means of a petroleum hydrocarbon solvent the petroleumsoluble non-volatile constituents of said residual resin; a drying oil, a drier, and a volatile solvent for said residual resin.

3. A varnish, characterized by its resistance to the solvent effects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble resin obtained by first extracting pine wood with a coal tar hydrocarbon solvent, second removing the volatile constituents from said extract and leaving a residual resin, then third extracting from said residual resin and by means of a petroleum hydrocarbon solvent the petroleum-soluble non-volatile constituents of said residual resin; linseed oil, and a volatile solvent for said residual resin.

4. A varnish, a characterized by its resistance to the solvent effects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble resin obtained by first extracting pine wood with a coal tar hydrocarbon solvent, second removing the volatile constituents from said extract and leaving a residual resin, then third extracting from said residual resin and by means, of a petroleum hydrocarbon solvent the petroleumsoluble non-volatile constituents oi said residual resin; China-wood oil and a volatile solvent for said residual resin.

5. A varnish, characterized by its resistance to the solvent effects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble resin obtained by first extracting pine wood with a coal tar hydrocarbon solvent, second removing the volatile constituents from said extract and leaving a residual resin, then third extracting from said residual resin and by means of a petroleum hydrocarbon solvent the petroleum-soluble non-volatile constituents of said residual resin; a drying oil, a metal linoleate and a volatile solvent for said residual resin.

6. A varnish, characterized by its resistance to the solvent effects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble resin obtained by first extracting pine wood with a coal tar hydrocarbon solvent, second removing the volatile constituents from said extract and leaving a residual resin, then third extracting from said residual resin and by means of a petroleum hydrocarbon solvent the petroleum-soluble non-volatile constituents of said residual resin; a drying oil and a volatile hydrogenated petroleum solvent.

'7. A varnish, characterized by its resistance to the solvent efiects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble resin obtained by first extracting pine wood with a coal tar hydrocarbon solvent, second removing the volatile constituents from said extract and leaving a residual resin, then tlilrd extracting from said residual resin and by means of a petroleum hydrocarbon solvent the petroleum-soluble non-volatile constituents of said residualresin; a drying oil, a drier, and a volatile hydrogenated petroleum solvent.

8. A varnish, characterized by its resistance to the solvent efiects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble leaving a residual resin, then third extracting from said residual resin and by means of a petroleum hydrocarbon solvent the petroleum-soluble non-volatile constituents of said residual resin; linseed oil, and a volatile hydrogenated petroleum solvent.

9. A varnish, characterized by its resistance to the solvent efiects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble resin obtained by first extracting pine wood with a coal tar hydrocarbon solvent, second removing the volatile constituents from said extract and leaving a residual resin, then third extracting from said residual resin and by means of a peetroleum hydrocarbon solvent the petroleum-soluble non-volatile constituents of said residual resin; China-wood oil and a volatile hydrogenated petroleum solvent.

10. A varnish, characterized by its resistance to Y the solvent efiects of unheated petroleum hydrocarbons such as gasoline, which includes as ingredients a petroleum hydrocarbon-insoluble resin obtained by first extracting pine wood with a coal tar hydrocarbon solvent, second removing the volatile constituents from said extract and leaving a residual resin, then third extracting from said residual resin and by means ofa petroleum hydrocarbon solvent the petroleum-soluble non-volatile constituents of said residual resin; a drying oil, a metal lineoleate and a volatile hydrogenated petroleum solvent.

FRED H. LANE. 

